Update README.md

Author: patinthehat

README.md

@@ -143,13 +143,14 @@ The `branch:recent` command can be run with the `--jira` flag to refine the orde
    - Visit <https://id.atlassian.com/manage-profile/security/api-tokens>.
    - Click **Create API token** and copy the generated value.
 
+```bash
    # Recommended: Use a secure credential manager or encrypted .env file
    # Store these credentials in an encrypted .env file, not in your shell profile
    export JIRA_API_TOKEN="your-token"
    export JIRA_SUBDOMAIN="acme"        # for 
    export JIRA_EMAIL_ADDRESS="you@example.com"
    export JIRA_EMAIL_ADDRESS="you@example.com"
-   ```
+```
 
    Add these to your shell profile or `.env` file so `git-ninja` can authenticate with JIRA.